1. Field of the Invention
The present invention relates to an ink-jet head which ejects ink onto a recording medium and a method of producing the ink-jet head.
2. Description of the Related Art
J. P. A. Publication No. 2004-114410 discloses an ink-jet head including (A) a flow-passage unit in which a plurality of individual flow-passages respectively extending from manifolds to nozzles via pressure chambers are formed and (B) an actuator unit fixed to the flow-passage unit and configured to apply a pressure to ink stored in the pressure chambers. In this ink-jet head, the flow-passage unit is formed by stacking a plurality of flat plates each having a plurality of holes formed therein each partially constituting ink flow-passages including the manifolds, the pressure chambers, and the nozzles. The plurality of holes are formed by etching or the like in the plurality of plates except a plate in which the nozzles are provided. The actuator unit is fixed onto one of the plates in which the pressure chambers are formed, and includes a common electrode, individual electrodes, and a piezoelectric sheet. The common electrode is disposed so as to extend over the pressure chambers, the individual electrodes are disposed in areas opposed to the pressure chambers, respectively, and the piezoelectric sheet is interposed between the individual electrodes and the common electrode. When an electric field is selectively applied to areas of the piezoelectric sheet which are sandwiched between the respective individual electrodes and the common electrode, areas of the piezoelectric sheet respectively opposed to the pressure chambers selectively deform into a convex shape that protrudes toward the respective pressure chambers. As a result, a volume of each of the selected pressure chambers is decreased to increase a pressure of the ink stored in each of the selected pressure chambers, whereby the ink is ejected from each of ones of the nozzles corresponding to the selected pressure chambers.